package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.Voucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IVoucherService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.springframework.aop.framework.AopContext;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;


    @Override
    public Result seckillVoucher(Long voucherId) {
        // 1. 查询优惠券信息
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        if (voucher == null)
            // 如果优惠券不存在，返回失败结果
            return Result.fail("优惠券不存在！");

        // 2. 时间判断
        // 检查秒杀是否尚未开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now()))
            return Result.fail("秒杀尚未开始！");

        // 检查秒杀是否已经结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now()))
            return Result.fail("秒杀已经结束！");

        // 3. 库存更新
        // 检查库存是否足够
        if (voucher.getStock() < 1)
            return Result.fail("库存不足！");

        Long userId = UserHolder.getUser().getId();

        synchronized (userId.toString().intern()) {
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        }
    }

    @Transactional
    public Result createVoucherOrder(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
            int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
            if (count > 0)
                return Result.fail("用户已经购买过一次！");

            // 尝试更新库存，减少库存数量
            boolean success = seckillVoucherService.update()
                    .setSql("stock = stock - 1")
                    .eq("voucher_id", voucherId)
                    .gt("stock", 0)
                    .update();


            if (!success)
                // 如果更新库存失败，返回失败结果
                return Result.fail("库存不足！");


            // 4. 创建订单
            VoucherOrder voucherOrder = new VoucherOrder();
            // 4.1 生成订单ID
            long orderId = redisIdWorker.nextId("order");
            voucherOrder.setId(orderId);
            // 4.2 设置用户ID

            voucherOrder.setUserId(userId);
            // 4.3 设置代金券ID
            voucherOrder.setVoucherId(voucherId);
            // 保存订单
            save(voucherOrder);

            // 返回成功结果，包含订单ID
            return Result.ok(orderId);

        }

}
